Safety device for steam-boilers



(No Model.)

W. CHRISTENSEN. I SAFETY DEVICE FOR STEAM BOILERS. N0. 536,128.

Patented Mar. 19, 1895.

I W imas cov, PHOTCLITHQ WASHINGTON. a. c.

fUNirso STATES 'AT NT FFICE.

'WILLlAll/LCHRISTENSEN, or PHILADELPHIA, PENNSYLVANIA.

S-AFETY DEVICE FOR STEAM-BOILERS SPECIFICATION forming part of Letters Patent No. 536,128, dated March 19, 1895.

Application filed February 14, l894. Renewed December 15, 1894. Serial No. 531,971. (No model.)

i the following is a specification.

My invention'has relation to safety devices for steam boilers; and it relates more particularly to the arrangement ofa fusible plug in connection'with certainmechanism in proximity to the boiler asameans of safety and adapted to operate in the event of the fluid of the boiler sinking. below the normal line thereof.

The principal object of my invention is to provide a simple, inexpensive and efficient safety device for a steam boiler and so arranged in connection with the piston and valve of the feed pipe ofthe boiler as to automatically operate the valve thereof in the event'of the fluid of the boiler sinking or falling below the normal water line therein by the melting of a fusible plug by the steam of the boiler .and of the same then pressing against the piston of a cylinder to actuate by the movement of the piston the said valve connected with the feed water pipe of the boiler. 1

My invention stated in general terms, consists of a boiler provided with a controlled pipe connection having a fusible plug inter posed therein and adapted to establish a direct connection with a cylinder having a piston adapted to operate levers connected with a valve of the feed pipe of the boiler; and my invention further consists of the improvements hereinafter described and claimed.

The nature and scope of my invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof, and in which Figure 1, is a View partly in front elevation and partly in section of a steam boiler with a fusible plug safety device of my invention shown in application thereto; and Fig. 2, is a view partlyin vertical central section through the fusible plug and a cylinder and piston and in elevation the levers'and feed pipe of the boiler operated thereby, of Fig. 1, showing the detailed construction and arrange- :ment thereof.

' Referring to the drawings A, is the boiler of any suitable construction and arrangement showing the normal water line y, therein.

1), is a pipe connected with the head a, of the boiler, and provided with a stop-cock b.

c, is a circular offset formed in the pipe I), and having'a threaded internal surface 0, for the reception of a partially threadedfusible plug 0. The pipe 19, is extended and provided with a section b secured into. or formed integral with a cylinder D, and providing thereby an inlet to the interior thereof.

d, is a piston adapted to be afforded an up and down movement and provided with a rod or stem d, pivoted at its opposite end to a rocking beamd pivotally supported at 01 from the head a, of the boiler A. At the opposite end of the rocking beam (1 is pivoted thereto a lever d, which is pivoted at its opposite end to the arm d of a cut-off valve e, suitably mounted in a water feed pipe E, connected with the boiler A, and depending therefrom.

The operation'of the safety device hereinbefore described,is as follows: It must be assumed that the fusible plug 0, occupies the position shown in Figs. 1 and 2, and that the mechanism adapted to be actuated to operate the valve 6, of the pipe E, is in the position shown and with the stop-cock b',open. If the fluid in the boiler A, should for any cause sink or fall beneath the low water line 00, inthe sectional view of Fig. 1, the steam will enter the pipe I), andin its passage will melt the fusible plug 0, thereby forcing itself in a forward direction through the pipe 19 connected with the cylinder D, raising the piston'therei n, which in turn by means of its stem or rod 61', will rock the beam d and operate in a downward direction the lever (1 to automatically actuate the arm d of the valve e, of the pipe E, to open the same and to permit water to flow into the boiler A, thereby preventing bursting thereof. When the boiler has been again filled with a fluid or restored to its normal state or condition by turning the stop-cock b, so as to prevent the passage of steam from the boiler through the pipe 5, another fusible plug 0, may be inserted to place in the offset portionc, thereof adapted beam' actuating a lever pivoted to the arm of a valve in a feed pipe connected with the boiler, substantially as and for the purposes set forth.

2. A safety device for boilers, comprising a pipe connected with the head of the boiler at seams vor about the low Water line thereof and provided with a stop-cock, an offset adjacent thereto with a threaded wall, a fusible plug engaging said olt'set and the latter having a connection with a vertical cylinder, a piston movable therein and provided with a stem pivoted to a supported rocking beam in pivotal connection with a lever attached to the operating, arm of a cut-0E valve of a pipe secured into the boiler and depending therefrom, substantially as and for the purposes set forth.

In testimony whereof I have hereunto set my signature in the presence of two subscribing witnesses.

WILLIAM CHRISTENSEN.

Witnesses:

CHAS. DUNKER, WILLIAM H. Cox. 

